Elevating- truck



Feb. 20, 1923. 1,445,838. I R. LOVEJOY.

' ELEVATING TRUCK. v

FILED SEPT 16, I916. 2'SHEETSSHEET lnv'emor. Ralph M. Lovejoy y M MMW Feb. 20, 1923.

H. M. LOVEJOY. ELEVATING TRUCK.

2 SHEETS-SHEET 2.

FILED SEPT 16. 1916.

Invenror. Ralph. M. Love oy b yi dm afmmt" Patented l 29,

tease RALPH M. LOVEJ'OY, OFil'IEREDI'lI-I, NEW' HMPSHIRE, ASSIGNOR TO LEWIS- SI-IEPARD COIMIIANY, OF BOSTON, ll 'fASSACI-IUSETTS, A CORPORATION OF IVIASSACHUSETTS.

nnnvn'rrne TRUCK.

Application filed SeptemberlG, 1916. Serial No. 120,557.

To all whom if; may concern Be it known that I, RALPH M. LovnJoY, a citizen of the United States, and resident of Meredith, county of Belknap, State of New Hampshire, have invented an Improvement in Elevating Trucks, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representingv like parts. V 7

This invention relates to improvements in elevatin trucks 'in' which the platform is raised fromthe main frame by depressing the, steering handle, and particularly of the type in which the load is raised or jacked up step by step.

The principal object of the invention is to provide mechanism forelevating the platform, ofsuch a character that-the truck may be madein any desirable length or size without other substantialchanges than in the length ofthe frame andplatfo'rm and such structural modifications as may be desirable to adapt the truck to' the maximum load to be handled.

Another object ofthe invention is to provide an improved elevating mechanism which will be adapted'to-lraise heavyloads more easily and to a greater height from the floor than is customary.- I,

Another object of the invention is to provide a simplified form of elevating mechanism which can be easily constructed, which will withstand hard usage without breakage and which may be operated to raise the plat form step by step with the tongue in any steering position. v 1

In the drawings;

Fig. 1 is avertica-l sectional view of an elevating truck embodying my invention, taken on lines 1-'-1 Fig. 2,- s

Fig. 2 is a plan view of thesame the steering handle being shown in section,

Fig. 3 is an enlarged detail view of the platform locking-mechanism and the means for releasing thesame, and,

Fig. 4 is an enlarged detail View of the dash pot, showing the same mainly in vertical. longitudinal section.

The elevating truck disclosed herein isof the same general type'as that which is described in my prior Patent No.'1,307,687, granted June 2 1919. In that construction the elevating mechanism comprised a scale beam mechanism whichrequired levers of different lengths for different sizes of trucks.

The present invention contemplates the use of standard elevating mechanism which may be used in the manufacture of trucks of differentdengths with the mere introduction of a link of the required length, thus enabling a greater number of standard sizes to be made economically and orders for special sizes'to'be filled promptly and without substantial additional expense In order to accomplish this purpose the front end of the truck, where the main elevating means is located is provided with a lever which is operated by the raising and lowering of the tongue; The rear end of the load supporting means or platform is carried by a separate elevating mechanism which is connected to said leverbya link or other suitable tension or compression member which maybe constructed in-the different lengths required for different sizes or styles of trucks. i

The preferred form of truck illustrated herein comprises the usual main frame having a front steering wheel,a pair of rear wheels, and a platform movable substantially vertically in respect to the main frame. The front end of the platform preferably is directly supported upon a lever mechanism 8 which is operated by a lifting instrumentality operated in a manner analogous to a lifting jack, while the rear end of the truck is independently supported by a toggle or cam preferably operable by the lever which supports the front end, the lever and toggle being connected by a link which may be varied to suit the desired length of truck.

The truck frame comprises the usual side rails 1, 2 which preferably are angle plates of rolled steel orv malleable castings connected together at the front endby an arched girder 3 having acentral cylindrical boss 4 toreceiv'e a post 5 extending upwardly from the steering wheel and which is provided the axles 10. By this construction the rotation of the axle in its bearings prevents the wearing of the axle upon one side which would occur if the axle were rigidly secured to the brackets 9.

The brackets 9 have do\\"nwa1.'d and rearward extensions 12 which provide journals for a shaft 13 which supports toggle links 14.- having at their opposite ends apertures to receive a shaft or pintle 15. A co-operating toggle member 16 which is pivoted upon the shaft 15 and sup orts the rear end of the platform preferab comprises a web recessedcentrally to accommodate the operating link and providing members 17 which are pivoted upon the shaft 15. The toggle member 16 preferably has cylindrical integral extensions 18 which are apertured axially to receive a shaft 19 which is secured to, or journalled in, brackets 20, bolted to the side bars 21 of the platform.

The platform, as illustrated herein is of a skeleton construction comprising the side bars 21, preferably angle 'irons of rolled steel or malleable castings, a connecting rear end plate 22, and front standards 23 having extensions 24 connected to the under sides of the sidebars 21 and joined by cross bars 25,26.

The front end of the platform is suported by lever mechanism preferably in the orm of a lever 27 having a flat web-like coir struetion with longitudinal apertures adjacent to and parallel with its edges to receive pivotal shafts 28, 29, one of said shafts, 28 bein 'journalled in brackets or standsBO which are supportedupon and secured to the siderails 1, 2 of the main frame, and the other shaft 29 pivoted in suitable hearings in a depending web of the extension 24 of theplatform standard 23.

Thelever member 27 has a central trans verse, downwardly projecting web 31 which extends both forwardly and rearwardly, the forward extension 39. being pivotally connected to an elevating link 33 and the rearward extension34 to a link 35 which is pivotally joined to the front end of another link 36 which is pivoted at its rear end upon the shaft 15 between the extensions 17 of thetoggle member 16.

By reason of this construction the elevation of. the link by the jacking mechanism hereinafter described, or by other suitable means, will oscillate the lever 27 about its fulcrum 28, thus raising the front end of the platform while the opposite oscillation of the rearward extension 34 of said lever will draw the link 35 forward and by straightening the toggle members 14, 16 will raise the rear end of the platform.

When the link is elevated and its pivotal connection 29 is raised through the arc of a circle it causes the platform to be moved forward. during preferably the first half of the elevating movement thereby moving the toggle members 14 and 16 into a more effective position. Upon the remaining upward movement of the lever 27 the platform is moved backward thus further assisting in straightening the toggle links and so positioning the platform that there is no substantial resultant relative longitudinal movement between it and the frame.

The link 36 desirably may be so disposed as to rest upon the rear axle 10, extending angularly downward therefrom when the platform is lowered so thata lifting leverage will be exerted upon the toggle during the initial movement of the links 35, 36 which will facilitate their movement in starting to raise the load when the toggles are in the most unfavorable position.

Inasmuch as the lever mechanism which elevates the front end of the platform and the toggle mechanism which raises its rear end are separate mechanisms conjointly operable through the links 35, 36 t-hey may be used in the manufacture of trucks of any length by varying the length of the link 35 as is necessary to conform to the desired length of truck. This feature is very important in the commercial manufacture of trucks as the various users demand trucks of lengths suited to their peculiar needs.

Any suitable mechanism may be utilized for actuating theelevating mechanism, such as the step by step elevating mechanism disclosed in my prior application aforesaid which comprises interengaging means connected respectively to the tongue and the platform operable by the vertical movement of the tongue to elevate the platform, means being provided for locking the plat form at each step of elevation. In the present improved construction the interengaging means are so constructed that they may be disengaged by the action of gravity when the platform is locked in elevated position, by merelv raising the tongue a short distance. By thus disengaging the interengaging means the tongue is freed to steer the truck and furthermore the load may be dropped by releasing the locking mechanism without causing the tongue tofly up.

It will be readily appreciated that-by thus automatically releasing the interengaging members when the loaded platform has been elevated considerable time is saved and the possibility of injury to the employee by aflying tongue occasioned by accidental unlocking of the platform is avoided. As

shown in the accompaning drawing the elevating link 33 is pivotally-eonnected at. its

upper end to a toothed sector 37 which is pivoted upon a pin 38 which passes through ears upon the upper ends of thestandard sections 23. f l I y I Thesector 37 is actuated by a lever comrising two parallel arms 39 which are pivoted at one end upon the pin 38 and are connected at the other to a block 40 which is engaged by suitable means adapted to be operated by raising and lowering the steering tongue. A pawl 41 rigidly secured to a rock shaft 42 journalled in the arms 39 engages the teeth 37 of the sector 37 so that the raising and lowering of the lever arms 39 serves to raise the sector 37 step by step and with it the elevating link 33, suitable means being provided to retain the link 33 at each step of elevation. A weighted arm 43 -(see Fig; 2) fixedly secured to the rock shaft 42 normally holds the pawl 41 in engagement with the teeth of the sector and also serves to rotate the pawlout of engagement with the" sector when the latter is raised beyond the last tooth, so that the sector is freed to permit the descent of the platform upon release of its locking mechanism. 1

I The'lever arms 39 preferably are actuated bymeans operable 'by the steering tongue when the latter is in any steering position.

As illustrated herein thetongue e l, having the usual handles 45;'1s seated in a socket 4&6 in a lever 47 havingtrunnions 48 ournalled 'in ears 49. extending upwardly and forwardly from a split sleeve 50 securely clamped upon the post of the steering wheel. by a bolt 51 passingthrough ears extending from said sleeve. The lever 47 has an extension 4; X whichis pivotally connected to thelowerendof 'a strut .52 which extends vertically upward in line with the axis of the postof'the steering wheel and is pivoted at its upper end to a block 53 which in turn is pivoted in ears 54 of a coupling having astem 55 journalled in the, block 41 which connects the free ends of the lever arms 39. By this construction a universal joint is formed which will enable the lever arms 39 to be operated with the tongue in any steering position] Furthermore the universal joint will not only permit the steering wheel to bepositioned as desired but will also allow the arcuatemovement of the end of the arms 39 without binding.

The extension 47* of the lever 4:7,prefer ably has a flat end adapted to engage the upper end of the steering post and collar 50 so that the truck can be pushed when the tongue is in vertical position. This feature is important as it isfrequently necessary to push the truck, in'a restricted Space, beneath the articles to be moved, or to-position the truck for unloading. It is also found that the truck can be pushed more easily than pulled, and, as the steering wheel can be turned by the operator when pushing the truck as well. as when pulling it, this construction is found to be very advantageous.

Any suitable means may be used in connection with the elevating mechanism for applied to one of the members to disengage it from theother. In such instances the interengaging portions of the locking members are quickly worn and frequently are broken. The present invention contemplates the employment of. a locking mechanism which includes a toggle the members of which when straightened so that the pivotal axes of the links of the toggle are in substantial alinement will form a rigid strut which will hold the interengaging members in locking position. This toggle however, may be easily broken to permit the interengaging members to separate and the load to descend. By the use of such mechanism the elevating *means may be operated to raise the platform ly necessary to breakthe toggle to free the will descend freely.

A suitable cushioning device such as that hereinafter described may be used to gradually arrest the descent of the platform.

The preferred mechanism which is illustrated herein ."for locking the elevating interengagin members and the platform mechanism as it is raised step by step com-.

prises a ratchet plate 56 which is riveted or bolted to the elevatin link 33 (see Figs 1 and 3) and is engaged by a pawl 57 which depends from the upper end of a link 58 which is pivoted at its lower end upon a shaft 59 mounted in abracket 60 which is bolted upon across girder 61 connecting the side plates 1, 2 of the main frame.

The pawl preferably is actuated by an elbow joint connection or toggle-like construction comprising a link 62 pivotally connected at one end to the pawl 57 and at its opposit'eend to an arm 63 fixed upon a rock shaftbt which is 'journalled in an ear 65 extending laterally from the link The opposite end of said rock shaft has a crank arm 66 which'is connected by a link to a foot lever 68 which is fulcrumed uponthe shaft 59. A spring 69 connected at one end to the crank arm 66 and at its opposite end to a pin on the link F8 nornialty tends to straighten the toggle members 62, 63 and force the pawl 57 into locking engagement with the teeth of the ratchet plate 56. A. stud 63* projecting from the sides of the link 58 serves to limit the movement of the links to locking position.

In order to elevate the platform, the steering handle is alternately raised and lowered to cause the lever arms and dog 5 4t to raise the sector and with it the elevat ing link 33 thereby actiuiting the lever 32 toraisc the front end of the platform while its rear end is simultai'ieoiisly elevated by the toggle .lrfl lG. At each step the elevating link is locked against descent by the and the proportionsot' the sector teeth 37" and the teeth of the ratchet 56 are such that the lifting movement for each step of elevation can be accomplished only during the swinging movement of the tongue from substantially the vertical position illustrated in Fig. 1 through an are located above the effective hauling position of the tongue.

In the present embodiment of the invention the teeth of the ratchet 56 are of such length that when the tongue is swung from a vertical position through a predetermined are above the normal steering position of the tongue, the locking pawl 57 will engage the next tooth of the ratchet, but further downward movement of the tongue cannot cause the ratchet to be raised sufliciently to cause the locking dog 57 to engage the next lower tooth. Consequently, the weight of the load will remain upon the tongue it the tongue is swung below said predetermined arc until. the tongue is raised sufiicient-ly to enable the pawl to engage the tooth which it has passed in the downward swinging lllUVQll'lGl'lt.

This constructioi'i requires the operator to release the lifting pawl 41 from engagement with the sector teeth 37" in order that the weight may be removed from the tongue when the latter is moved to an effective steering position and is utilized to pull the truck. By thus requiring the pawl 41 to be released from engagement with the sector teeth 37 during the normal hauling of the truck accidental tripping of the locking mechanism can never cause the tongue to fly up and injure the operator or a bystander.

When the sector has reached its highest position the weighted pawl 41 falls away from the teeth 37 oi the sector so that the sector may be returned without obstruction to its initial position. \Vhen the loaded platform is thus elevated the truck is pulled or pushed to its destination. The operator thereupon depresses the foot lever 68 thereby actuating the crank 66 of the rock shaft (5-! to break the locking toggle 62, 63, thus releasing the pawl 57 from its engagement with the teeth of the ratchet plate 56 and permitting the link 33, and the platform which it sustains, to descend.

The descent of the platform may be cushioned by any suitable means. I have however devised a special form of dash-pot particularly adapted for use with loads of different weight which will be properly responsive to all requirements.

In usual types of dash-pots those designed to cushion a heavy load work tooslowly when used with a light load, while those designed for light loads are insufficient to cushion th descent of heavy loads. By my novel construction means are provided which offers greater resistance to the descent of heavy loads than to that of light loads or the empty platform so that the platform is permitted to descend with substantially equal speed under all conditions. This is accomplished by providing means for causing the fluid of the dash pot to follow an extended irregular path with bafiles so interposed as to offer greater resistance to the flow of the fluid substantially in proportion to the pressure of the fluid.

The preferred form of dash pot illustrated herein comprises a cylinder of brass or steel tubing having a cap7 6 screw threaded thereon, the cap being provided with ears 77 which are pivotally mounted upon 3 lug or bracket 78 on the transverse girder 61, and a tubular piston 80 telescopically fitting the cylinder 75 and having at its upper end a cap 81 provided with ears 82 which are ivotally connected to the oil'set end 83 of an arm 84 which in turn is pivoted to the ole rating link The piston cap 81 desirably is formed in tegrally of sections having different diameter, the intermediate section being very slightly larger than the outer diameter of the cylinder 75 while the lower section or boss 81 fits tightly within the bore of the tubular piston 80. The upper end of the piston 80 abuts against the lower face of the intermediate portion of said cap and is secured to the boss 81 by a pin 85 thus forming a very rigid construction.

The lower end of the tubular piston is provided with a head 86 having the same diameter as the tubular piston and preferably having an integral boss adapted to be screwed into the lower end of the piston 80.

The piston head 86is provided with a central aperture 87 having screw threaded walls and also with a countersunk portion forming an annular recess 88 adjacent'the lower mouth of said aperture. A nut or plug having' a threaded stem 89 is seated in Said aperture, thehead 90- of said plug being larger in diameter than that'ot the annular recess 88. Small holes or ducts 91 lead ironithe cylinder ClIZIHIlJElQQ'lZO the annular recess 83 and ducts 98 lead from said recess: to a central outlet 94 in the stem 89 of the plug, thus providing an irregular course for the fluid in the dash pot adapted to retard its j flow as the piston is moved in said cylinder. v

In order to impose still further resistance to the flow of the fluid a second plug 95 may be screwed into the upper end of the aperture 87, said" plug being provided with a central passage 96 having lateral outlets 97.

The plug 95 preferably is surrounded by a two part casing comprising complementary hollow members 98, 99 which clamp between them a disk 100 which divides the space enclosed by said hollow members into twochambers 101-, 102, the disk 100 having a central. recesso't sutliciently larger diameter than that of the plugto permit the fluid to flow slowly from the chamber 101 to the hamber 102. Outlet orifices 103 lead from the chamber 101 to the interior of the tubular piston. .By providing the upper end of the plug 95 with an enlarged square or hexagonal head the casing members 98, 99 and disk 100 may be clamped firmly in place by the plug when it is screwed into the aperture 87. By this construction considerable additional resistance is presented to the How otthefluid, since after it issues from the outlet 94 of the piston headit passes into the aperture. 87 thence through the orifice 96 and its angularly disposed outlets 97 to the chamber 102 where it flows against the walls of the chamber; Thence the fluid flows through the central recess in the disk 100 into the chamber 101 and finally from said chamber thro-ugh the outlets108 into the hollow piston. By thus causing the fluid alternately: to pass through an irregular course of small ducts intorelatively large chambers the fluid is enabled to flow relatively freely when the piston is moved slowly or under light load but is caused to eddy andto otter greatly increased resistance as the pressure upo-nthe piston is in creased so that the dash pot operates properly to cushion loads of any desired weight with substantially the same piston speed.

In order to permit the piston to be raised without resistance-the head 86 is provided with a large orifice 104 and a communicating countersunk portion 105, the walls of which form a seat for a ball valve 106. The countersink 105 may be so locatedthat the head90 oi the lower plug overliesa portion of the same and serves to retain the ball valve in its clramberli length when the As there is a tendency of the fluid in the 9 the piston is provided at a distance from its head, with aplurality oi external annular grooves 107 which communicate with the interior of the piston through orifices 108 so that the fluidwhich creeps up between the piston and cylinder will be returned to the body of fluid and will be prevented from working .out of the top of the cylinder. A felt packing 109 may be provided to absorb any of the fluid which may work beyond the grooves 107 and to exclude dust.

The piston also desirably is provided with a. cylindrical dust guard or apron 110 which is connected to the intermediate portion of the cap 81 and fits l oosely around the cylinder and extends practically its entire piston in depressed positione it is to be understood that the embodiment of my invention disclosed. herein is illustrative and not restrictiveand that various changes in the mechanism and substitution of equivalent instrumentalities may be made within the meaning and scope of the following claims.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is;

1. In an elevating truck comprising steering mechanism, a tongue mounted to swing vertically, load supporting means, a lever at the front end of said truck operable by the vertical movement of said tongue when in any steering position, elevating means for supporting the rear end of said load supporting means, and means including a link connecting the rear elevating means to said lever operable by the movement of said lever simultaneously to elevate the rear end of said load supporting means.

2. In an elevating truck comprlsing a rear axle and having steering mechanism including'a tongue mounted to swing vertically, a

load supporting means, a lever at the front end of said truck operable by the vertical movement'of said tongue when in any steering position, elevating means connected to the rear axle and tosaid load supporting means and means including a link connecting said rear elevating means and said lever operable-by, the movement of said lever simultaneously to elevate the rear end of said load supportingmeans.

In an elevating truck comprising steerin mechanism including a tongue mounted to swing vertically, load supporting means,

means for el.evatingthe front end of said load supportlng means step by step including alever pivotally connected to the front end of said load supporting means operable by the vertical movement of said tongue,

means tor-locking the load supporting means against descent at each step of elevation, elevating meansfor supporting the rearend of said load .supporting means and means including a link connecting the same to sa d lever and operable by the movement of said lever simultaneously to elevate the rear end of said load supporting means.

4. In an elevating truck comprising steering mechanism including a tongue mounted to swing vertically, load supporting means, means connected to and supporting the front end-of said load supporting means operable by the vertical movement of said tongue to elevate the frontend of said load supporting means, and means including a toggle supporting the rear end of said load support ng means, means operable by the elevating movement of the front elevating means simultaneously to actuate saidtoggle including a linkand supplemental means for giving an initial movement to said toggle.

5. In an elevating truck comprising steering mechanism including a tongue mounted to swing vertically, load supporting means, means connected to and supporting the front end of said load supporting means operable by the vertical movement of said tongue to elevate the front end of said load supporting means, means including a toggle supporting the rear end of said load supporting means, means operable by the elevating movement of the front elevating means simultaneously to actuate said toggle including a lever connected to the joint of said toggle and to said link for giving initial movement to said toggle.

6. In an elevating truck comprising a frame having a front supporting wheel and a vertically swinging tongue mounted thereon, a platform, a lever fulcrumed upon said frame and pivotally connected to and supporting the front end of said platform, jack lifting means for actuating said lever step by step to effect the raising of its pivotal connection with the platform, toggle mechanism supporting the rear end of said platform and means connecting said lever and said toggle mechanism adapted upon actuation of said lever simultaneously to operate said toggle mechanism whereby both ends 'of said platform Will be elevated vertically in respect to said frame without substantial relative longitudinal movement.

7. An elevating truck comprising a load supporting means, wheels, a steering mechanism including a tonguemounted to swing vertically, a member ivotally mounted up on said load supporting means, a co-operating member operable by the vertical swing ing movement of said tongue, having pawl and ratchet interengagement with said pivotally mounted member, a lever lying beneath and pivotally connected to said load supporting means, means connecting said lever to said pivotally mounted member, elevating means for the rear-end of said platform and a link connecting the same to said lever operable by the movement of said lever to actherewith a 00-0 eratin member 0 erable by the vertical swinging movement of said tongue, having pawl and ratchet interengagement with said pivotally mounted member, a lever lying beneath and pivot ally connected to said load supporting means, means connecting said lever to said pivotally mounted member, elevating means for the rear end of said platform, a link connecting the same to said lever operable by the movement of said lever to actuate said rear end elevating means, and a pawl and ratchet mechanism acting upon said pivotally mounted member to lock the same at each step of elevation whereby one of said 00- operating interengaging members may be moved relatively to the other to permit engagement of said pawl with successive teeth upon said ratchet.

' 9. In an elevating truck comprising a frame having rear wheels, a front steering wheel and tongue and a relatively movable platform; lever mechanism fulcrumed upon said frame supporting the front end of said platform, toggle mechanism supporting the rcar'end of said platform, means operatively connecting said lever mechanism and said toggle mechanism and rack and pawl mechanisms operable by raising and lowering said tongue adapted to actuate said lever mechanism to raise said platform vertically step by step;

10. In an elevating truck comprising a frame having rear wheels, a front steering wheel and tongue and a platform; lever mechanism fulcrumed upon said frame'supporting the front end of said platform, toggle mechanism supporting the rear end of said platform, means operatively connccting said lever mechanism and said toggle mechanism, a standard, a toothed sector pivotally mounted upon said standard, a link connecting the same to said lever mechanism. means for raising said sector step by step to elevate said platform and means for locking the platform against descent at each step of elevation.

11. In an elevating truck comprising a frame having rear wheels. a front steering wheel and tongue and a platform; a standard. lever mechanism fulcrumed upon said frame supporting the front end of said platfornntoggle mechanism supporting the rear end of said. platform, means operatlvely connecting said lever mechanismxand saidtoggle nieihanism, a toothed sector pivotally mounted upon said standard, a link connecting the same to said lever mechanism, means operable by raisingandlowering said tongue for raising said sector step by step to elevate said platform,'means for locking saidplatform against descent, comprising a ratchet upon said link, a pawl pivotally supported by said frame, means for locking ard, lever mechanism fulcrumed upon said frame supporting the front. end of said platform, toggle mechanism supporting the rear end of said platform, means operatively connecting said lever mechanism and said toggle mechanism, a toothed sector pivotally mounted upon said standard, a link connecting vthe same to said lever mechanism,

means for raisingsaid sector step by step, comprising a lever pivoted on said standard having a pawl engaging SaldSGCtOI,

means'operable by said tongue when in any steering position to reciprocate said lever to raise the platform step by step and means for locking the platform at each step of elevation comprising a ratchet upon said link, a pawl pivotally supported by said frame, a spring actuated means normally locking said pawl 1n engagement with said ratchet and means for breaking said locking means.

13. In an elevating truck comprising a frame having rear wheels, a-front steering. wheel and tongue and a platform; lever mechanism fulcrumedupon said frame supporting the frontend of said platform, toggle mechanism supporting the rearend of said platform, means operatively connect ingsaid. lever mechanism and said toggle mechanism, a standard on said platform, a toothed sector pivotally mounted upon said platform standard, a link' connecting the same to said lever mechanism, means for raising said sector step by step, means for locking said platform against descent comrisin a. ratchet 11 3011 said link a awl' z-s a l pivotally supported by said frame, means for locking said pawl in engagement with said ratchet and cushioning means pivotally supported by said frame and pivotally connected to said link. i

14-. In an elevating truck comprising a main frame and arelatively movable platform, means for elevating said platform and releasable means for locking the same in elevated aositiona fluid contain'in dash ot operatively connected'gto said frame'and platform, comprising a cylinder and a piston reciprocable thercln and means for causing thefluid to exert a resistance to the descent of'the platform substantially proportionate to the weight of the load whereby the platof the fluid through said piston to cause said fluid to offer a resistance to the descent of the piston substantially proportionate to the weight of the load whereby the plat form- Will descend at substantially the same rate of speed under different loads.

16. In an elevating truck comprising a main frame and a relatively movable platform, means for elevating said platform and releasable means for locking the same in elevated position; a fluid containing dash pot, operatively connected to said frame and platform, comprising a cylinder and a hollow piston reciprocable therein having a headapertured to permit the fluid to flow through the same, means for impeding the free flow ofsaid fluid and for causing the same to follow an irregular and eddying course during thedescent of the piston and thereby to cause said fluid to ofier' aresistance to the descent of the piston substantially proportionate to the weight of the load whereby the platform will descend at substantially the same rate of speed under different loads and a valve in said piston head adapted to permit free downward flow of said fluid during the elevation of said plston.

17. Inan elevating truck comprising a main frame and a relatively movable plat form, means for elevating said platform and releasable means for locking the same in elevated position; a fluid containing dash pot, operatively connected to said frame and platform, comprising a cylinder and a hollow piston reciprocable therein having a having outlets so disposed as to cause the fluid to follow an irregular and eddying course whereby said fluid, is caused to offer greater resistance to the descent of the piston'under heavy than under light loads upon said piston and a valve in said piston head adapted to permit free downward flow of said fluid during the elevation of said piston. lSpln an elevating truck comprising main frame and a relatively movable platform, means for elevating said platform and releasable means for locking the same in elevated position; afluid containing dash pot, operativcly connected to said frame and platform, comprising a cylinder and a hollow piston reciprocable therein having a head apertured to permit the fluid to flow through the same, a plug in said aperture having a central duct and lateral outlet branches, a casing comprising complementary hollowmembers enclosing said plug and clamped together between the head of said plug and said piston head, and outlets leading from the chamberformed by said hollow membersso disposed as to cause the fluid to follow an irregular and eddying course whereby said fluid is caused to offer greater resistance to the descent of the piston under heavy than under light loads upon said piston and a valve in said piston head adapted to permit free downward flow of said fluid during the elevation of said piston.

19. In an elevating truck comprising a main frame and a relatively movable platform, means for elevating said platform and releasable means l0! locking the same in elevated position; alluid containing dash pot-,operatively connected to said frame and platform, comprising a cylinder and a hollow piston reciprocable therein having a head apertured to permit the fluid to flow through the same, a plug in said aperture having acentral duet, a casing comprising complementary hollow members enclosing said plug and having an aperture d plate therebetwecn to form two chan'ibers in said casing, the hollow casing members and baffle plate being clamped together between the head of said plug and the head of said piston, outlets leading from the duct in said plug intothe lower chamber and outlets leading from the upper chamber so disposed as to cause the fluid upon the descent of the piston to follow an irregular eddying course, and a valve in said head adapted to permit free downward flow of the fluid during the elevation of the piston.

20. In an elevating truck, comprising a main frame and a relatively movable platform, means for elevating said platform and releasable means for locking the same in elevated position; a fluid containing dash pot, operativcly connected to said frame and platform, comprising cylinder and a hollow piston reciprocable therein having a head apertured to permit the fluid to flow through the same and means communicating with said aperture. including alternating ducts of restricted area and relatively large chambers adapted to impede the flow of the fluid and to cause eddying thereof whereby said. fluid will offer a greater resistance to the descent of the pistons under heavy than under light loads and a valve in said piston head adapted to permit free downward flow of said fluid during the elevation of said piston.

21. In an elevating truck comprising a main frame, steering mechanism including a tongue mounted to swing vertically and a platform. inter-engaging means connected to said tongue and platform operable by the depression of said tongue to elevate the platform step by step, means for locking the Pldlll'OIIll in elevated position, said interengaging means being adapted to be disengaged by gravity upon raising the tongue when the platform is locked in a predetermined elevated position.

22. In an elevating truck comprising a frame, steering mechanism including a tongue mounted to swing vertically and a platform, elevating means for said platform including interengaging pivotally mounted members one of which. is connected to. said platform andthe other movable by depression of said tongue, having interengaging means operable. to raise the platform step by step upon repeated vertical swinging movements of said tongue, means for locking the platform in elevated position, one of said interengaging members being capable of swinging by gravity about its pivot and out of engagement with the other member when the. platform is locked in elevated position and the tongue raised.

23. In. an elevating truck comprising a frame, a platform having a standard, a toothed sector pivotally, mounted upon said standard, means connected to said sector operable by raising the latter to elevate said platform relative to said frame, steering mechanism including a tongue mounted to swing vertically, a dog normally engaging the teeth of said sector operable by the vertical movementof the tongue to raisesaid sector step by step, means for locking the platform at each step of'elevation and means for supporting said dog to permit the same to fall out of engagement with said sector 'upon raising the tongue after the dog has engaged the lowest tooth upon said sector and the load has been locked in elevated position.

24. In an elevating truck comprising load supportin means and means for elevating the same, means for locking said load supporting means against descent including a.

dog receiving member and a pivotally supported dog tending normally to swing away from engagement with said dog receiving member, means including a toggle for locking said dog in engagement with said dog receiving member and means for breaking said toggle whereby said dog willbe permitted to withdraw from engagementwith the co-operating dog receiving member and the load supporting means allowed to descend.

In an elevating truckcomprising a load suo wrting means and means a for raising said load supporting means, means for locking the load supporting means against descent including a'ratc'het and a pivotally supported dog tending normally to swing away from engagement with said ratchet,

means for locking-the dog in engagement with the ratchet including a toggle and means for breaking said toggle whereby said dog will be permitted to withdraw from engagement with said ratchet and the load supporting means allowed to descend. I

26. In an elevating truck comprlsing load supporting means, and elevating means for raising saidloadsupporting means, means for locking said load supporting means against descent including a ratchet'and a cooperating member pivotally supported at one end and having. at its opposite end a pivotally mounted dog adapted to engage the teeth of said ratchet, a toggle and meansfor actuating the same, means acting normally,

to straighten the links of said toggle to lock said dog in engagement with the ratchet and'means operable to break the toggle and thereby to release said dog from engagement with the ratchet.

27. In an elevating truck comprising a load supporting means and means for elevating said load supporting means, means for locking said load supporting means includlng a toggle having means acting normally to hold the axes of the links of said toggle in alinement and the toggle in lock-- ing position and means for breaking the toggle to permit the lockingmeans to be easily released while sustaining the load. I

28. In an elevating truck comprising a loadsupporting means and means for elevto swing vertically, load supporting means having a front standard, a member pivotally mounted onsaidstandard, means operable by the vertical swinging movement of said tongue when in steerin position, having pawl and ratchet connection with the end of said pivotally mounted member, a

lever lying beneath and pivotally connected to said load supporting means, means connecting said lever to said pivotally mounted member intermediate of the ends of the latter, means for elevating the rear end of said platform and a link connecting the same to said lever operable by the movement of said lever to actuate said rear end elevating means.

ally mounted on said standard, means oper- 30. Anelevating truck comprising steering mechanism including a tongue mounted to swing vertically, load, supporting means having a front standard, a member pivot-' able by the vertical swingingmovement of said tongue when in any steering position, having pawl and ratchet connection with the end of said pivotally mounted member, a lever lying beneath and pivotally connected to'said load supporting means, means connecting said lever to said pivotally mounted member intermediate of the ends of the latter, means for elevating the rear end of said platform, a link connecting the same to said lever operable by the movement of said lever to actuate said rear end elevating means, a pawl and ratchet mechanism acting upon said pivotally mounted member at a distance from its pivot for locking the same at each step of elevation whereby the pawl and ratchet connection between the pivotally mounted member and its actuating means and the pawl and ratchet locking mechanism move througha greater distance than that through which the load supporting means moves thereby enabling the use of relatively largeratchet teeth;

31. In an elevating truck comprising a load supporting means, means for elevating said load supporting means and means for locking the same in elevated position, means for cushioning the descent of the load supporting means including a dash pot having a liquid containing cylinder and a piston reciprocable therein and means for causing the liquid to exert a resistance to the descent of the platform proportional to the weight of the load. whereby the platform will descend at substantially the same speed under different loads. I

32. An elevating truck comprising steering mechanism including a tongue mounted to swing vertically, load supporting means, releasable interengaging members connecting said tongue to said load supporting means operable by said swinging movement of the tongue through an are located above the effective hauling position of the tongue to elevate the load supporting means step by step and locking means operable to lock said load supporting means only when said tongue is above said efiective hauling position whereby disengagement of said interengaging members will be required in order to permit the tongue to be freed from the weight of the load when moved to hauling position.

33. An elevating truck comprising steer ing mechanism including a tongue mounted to swing vertically, load supporting means, means for elevating the load supporting means including a lever pivotally connected to the front end of said load supporting means, pawl and ratchet mechanism operable by the downwainil movement of the tongue disengugen'lent of the lifting pawl and through an are located above the eifective ratchet will be required in order to permit hauling position of the tongue to elevate said the tongue to be freed from the weight of the 10 load supporting means step by step, a pawl load when moved to hauling position.

5 and ratchet operable to lock said load sup- In testimony whereof, I have signed my porting means only when said tongue is name to this specification. above its effective hauling position whereby RALPH M. LOVEJQY. 

